Hematuria and urinary bladder lesions compatible with bracken fern (Pteridium aquilinum) intoxication in captive fallow deer (Dama dama).

Hemangiosarcoma, hemangioma, transitional cell carcinoma, and chronic cystitis were diagnosed in the urinary bladder of six captive fallow deer (Dama dama). Hematuria and thin body condition were observed in the advanced cases. These findings were compatible with chronic enzootic hematuria and were suspected to have been induced by chronic ingestion of bracken fern (Pteridium aquilinum) present on the premises. These lesions were similar to those described in bovine enzootic hematuria in cattle. Hemangiosarcoma metastases, hydronephrosis, and renal carcinoma were also associated in some cases. This is the first report of hemangioma, hemangiosarcoma, transitional cell carcinoma, and renal carcinoma of the urinary bladder in fallow deer and the first indication of bracken fern intoxication in deer.